[linux-2.6-block.git] / drivers / net / can / sja1000 / sja1000.c

/*
 * sja1000.c -  Philips SJA1000 network device driver
 *
 * Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
 * 38106 Braunschweig, GERMANY
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2, in which case the provisions of the
 * GPL apply INSTEAD OF those given above.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * Send feedback to <socketcan-users@lists.berlios.de>
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/delay.h>

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>

#include "sja1000.h"

#define DRV_NAME "sja1000"

MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");

static struct can_bittiming_const sja1000_bittiming_const = {
	.name = DRV_NAME,
	.tseg1_min = 1,
	.tseg1_max = 16,
	.tseg2_min = 1,
	.tseg2_max = 8,
	.sjw_max = 4,
	.brp_min = 1,
	.brp_max = 64,
	.brp_inc = 1,
};

static int sja1000_probe_chip(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
		printk(KERN_INFO "%s: probing @0x%lX failed\n",
		       DRV_NAME, dev->base_addr);
		return 0;
	}
	return -1;
}

static void set_reset_mode(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	unsigned char status = priv->read_reg(priv, REG_MOD);
	int i;

	/* disable interrupts */
	priv->write_reg(priv, REG_IER, IRQ_OFF);

	for (i = 0; i < 100; i++) {
		/* check reset bit */
		if (status & MOD_RM) {
			priv->can.state = CAN_STATE_STOPPED;
			return;
		}

		priv->write_reg(priv, REG_MOD, MOD_RM);	/* reset chip */
		udelay(10);
		status = priv->read_reg(priv, REG_MOD);
	}

	dev_err(dev->dev.parent, "setting SJA1000 into reset mode failed!\n");
}

static void set_normal_mode(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	unsigned char status = priv->read_reg(priv, REG_MOD);
	int i;

	for (i = 0; i < 100; i++) {
		/* check reset bit */
		if ((status & MOD_RM) == 0) {
			priv->can.state = CAN_STATE_ERROR_ACTIVE;
			/* enable all interrupts */
			priv->write_reg(priv, REG_IER, IRQ_ALL);
			return;
		}

		/* set chip to normal mode */
		priv->write_reg(priv, REG_MOD, 0x00);
		udelay(10);
		status = priv->read_reg(priv, REG_MOD);
	}

	dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n");
}

static void sja1000_start(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	/* leave reset mode */
	if (priv->can.state != CAN_STATE_STOPPED)
		set_reset_mode(dev);

	/* Clear error counters and error code capture */
	priv->write_reg(priv, REG_TXERR, 0x0);
	priv->write_reg(priv, REG_RXERR, 0x0);
	priv->read_reg(priv, REG_ECC);

	/* leave reset mode */
	set_normal_mode(dev);
}

static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	if (!priv->open_time)
		return -EINVAL;

	switch (mode) {
	case CAN_MODE_START:
		sja1000_start(dev);
		if (netif_queue_stopped(dev))
			netif_wake_queue(dev);
		break;

	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int sja1000_set_bittiming(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct can_bittiming *bt = &priv->can.bittiming;
	u8 btr0, btr1;

	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
		(((bt->phase_seg2 - 1) & 0x7) << 4);
	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
		btr1 |= 0x80;

	dev_info(dev->dev.parent,
		 "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);

	priv->write_reg(priv, REG_BTR0, btr0);
	priv->write_reg(priv, REG_BTR1, btr1);

	return 0;
}

/*
 * initialize SJA1000 chip:
 *   - reset chip
 *   - set output mode
 *   - set baudrate
 *   - enable interrupts
 *   - start operating mode
 */
static void chipset_init(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	/* set clock divider and output control register */
	priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN);

	/* set acceptance filter (accept all) */
	priv->write_reg(priv, REG_ACCC0, 0x00);
	priv->write_reg(priv, REG_ACCC1, 0x00);
	priv->write_reg(priv, REG_ACCC2, 0x00);
	priv->write_reg(priv, REG_ACCC3, 0x00);

	priv->write_reg(priv, REG_ACCM0, 0xFF);
	priv->write_reg(priv, REG_ACCM1, 0xFF);
	priv->write_reg(priv, REG_ACCM2, 0xFF);
	priv->write_reg(priv, REG_ACCM3, 0xFF);

	priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL);
}

/*
 * transmit a CAN message
 * message layout in the sk_buff should be like this:
 * xx xx xx xx	 ff	 ll   00 11 22 33 44 55 66 77
 * [  can-id ] [flags] [len] [can data (up to 8 bytes]
 */
static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
					    struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct can_frame *cf = (struct can_frame *)skb->data;
	uint8_t fi;
	uint8_t dlc;
	canid_t id;
	uint8_t dreg;
	int i;

	netif_stop_queue(dev);

	fi = dlc = cf->can_dlc;
	id = cf->can_id;

	if (id & CAN_RTR_FLAG)
		fi |= FI_RTR;

	if (id & CAN_EFF_FLAG) {
		fi |= FI_FF;
		dreg = EFF_BUF;
		priv->write_reg(priv, REG_FI, fi);
		priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
		priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
		priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
		priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
	} else {
		dreg = SFF_BUF;
		priv->write_reg(priv, REG_FI, fi);
		priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
		priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
	}

	for (i = 0; i < dlc; i++)
		priv->write_reg(priv, dreg++, cf->data[i]);

	dev->trans_start = jiffies;

	can_put_echo_skb(skb, dev, 0);

	priv->write_reg(priv, REG_CMR, CMD_TR);

	return NETDEV_TX_OK;
}

static void sja1000_rx(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf;
	struct sk_buff *skb;
	uint8_t fi;
	uint8_t dreg;
	canid_t id;
	int i;

	/* create zero'ed CAN frame buffer */
	skb = alloc_can_skb(dev, &cf);
	if (skb == NULL)
		return;

	fi = priv->read_reg(priv, REG_FI);

	if (fi & FI_FF) {
		/* extended frame format (EFF) */
		dreg = EFF_BUF;
		id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
		    | (priv->read_reg(priv, REG_ID2) << (5 + 8))
		    | (priv->read_reg(priv, REG_ID3) << 5)
		    | (priv->read_reg(priv, REG_ID4) >> 3);
		id |= CAN_EFF_FLAG;
	} else {
		/* standard frame format (SFF) */
		dreg = SFF_BUF;
		id = (priv->read_reg(priv, REG_ID1) << 3)
		    | (priv->read_reg(priv, REG_ID2) >> 5);
	}

	if (fi & FI_RTR) {
		id |= CAN_RTR_FLAG;
	} else {
		cf->can_dlc = get_can_dlc(fi & 0x0F);
		for (i = 0; i < cf->can_dlc; i++)
			cf->data[i] = priv->read_reg(priv, dreg++);
	}

	cf->can_id = id;

	/* release receive buffer */
	priv->write_reg(priv, REG_CMR, CMD_RRB);

	netif_rx(skb);

	stats->rx_packets++;
	stats->rx_bytes += cf->can_dlc;
}

static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf;
	struct sk_buff *skb;
	enum can_state state = priv->can.state;
	uint8_t ecc, alc;

	skb = alloc_can_err_skb(dev, &cf);
	if (skb == NULL)
		return -ENOMEM;

	if (isrc & IRQ_DOI) {
		/* data overrun interrupt */
		dev_dbg(dev->dev.parent, "data overrun interrupt\n");
		cf->can_id |= CAN_ERR_CRTL;
		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
		stats->rx_over_errors++;
		stats->rx_errors++;
		priv->write_reg(priv, REG_CMR, CMD_CDO);	/* clear bit */
	}

	if (isrc & IRQ_EI) {
		/* error warning interrupt */
		dev_dbg(dev->dev.parent, "error warning interrupt\n");

		if (status & SR_BS) {
			state = CAN_STATE_BUS_OFF;
			cf->can_id |= CAN_ERR_BUSOFF;
			can_bus_off(dev);
		} else if (status & SR_ES) {
			state = CAN_STATE_ERROR_WARNING;
		} else
			state = CAN_STATE_ERROR_ACTIVE;
	}
	if (isrc & IRQ_BEI) {
		/* bus error interrupt */
		priv->can.can_stats.bus_error++;
		stats->rx_errors++;

		ecc = priv->read_reg(priv, REG_ECC);

		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;

		switch (ecc & ECC_MASK) {
		case ECC_BIT:
			cf->data[2] |= CAN_ERR_PROT_BIT;
			break;
		case ECC_FORM:
			cf->data[2] |= CAN_ERR_PROT_FORM;
			break;
		case ECC_STUFF:
			cf->data[2] |= CAN_ERR_PROT_STUFF;
			break;
		default:
			cf->data[2] |= CAN_ERR_PROT_UNSPEC;
			cf->data[3] = ecc & ECC_SEG;
			break;
		}
		/* Error occured during transmission? */
		if ((ecc & ECC_DIR) == 0)
			cf->data[2] |= CAN_ERR_PROT_TX;
	}
	if (isrc & IRQ_EPI) {
		/* error passive interrupt */
		dev_dbg(dev->dev.parent, "error passive interrupt\n");
		if (status & SR_ES)
			state = CAN_STATE_ERROR_PASSIVE;
		else
			state = CAN_STATE_ERROR_ACTIVE;
	}
	if (isrc & IRQ_ALI) {
		/* arbitration lost interrupt */
		dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
		alc = priv->read_reg(priv, REG_ALC);
		priv->can.can_stats.arbitration_lost++;
		stats->tx_errors++;
		cf->can_id |= CAN_ERR_LOSTARB;
		cf->data[0] = alc & 0x1f;
	}

	if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
					 state == CAN_STATE_ERROR_PASSIVE)) {
		uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
		uint8_t txerr = priv->read_reg(priv, REG_TXERR);
		cf->can_id |= CAN_ERR_CRTL;
		if (state == CAN_STATE_ERROR_WARNING) {
			priv->can.can_stats.error_warning++;
			cf->data[1] = (txerr > rxerr) ?
				CAN_ERR_CRTL_TX_WARNING :
				CAN_ERR_CRTL_RX_WARNING;
		} else {
			priv->can.can_stats.error_passive++;
			cf->data[1] = (txerr > rxerr) ?
				CAN_ERR_CRTL_TX_PASSIVE :
				CAN_ERR_CRTL_RX_PASSIVE;
		}
	}

	priv->can.state = state;

	netif_rx(skb);

	stats->rx_packets++;
	stats->rx_bytes += cf->can_dlc;

	return 0;
}

irqreturn_t sja1000_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	uint8_t isrc, status;
	int n = 0;

	/* Shared interrupts and IRQ off? */
	if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
		return IRQ_NONE;

	if (priv->pre_irq)
		priv->pre_irq(priv);

	while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
		n++;
		status = priv->read_reg(priv, REG_SR);

		if (isrc & IRQ_WUI)
			dev_warn(dev->dev.parent, "wakeup interrupt\n");

		if (isrc & IRQ_TI) {
			/* transmission complete interrupt */
			stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
			stats->tx_packets++;
			can_get_echo_skb(dev, 0);
			netif_wake_queue(dev);
		}
		if (isrc & IRQ_RI) {
			/* receive interrupt */
			while (status & SR_RBS) {
				sja1000_rx(dev);
				status = priv->read_reg(priv, REG_SR);
			}
		}
		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
			/* error interrupt */
			if (sja1000_err(dev, isrc, status))
				break;
		}
	}

	if (priv->post_irq)
		priv->post_irq(priv);

	if (n >= SJA1000_MAX_IRQ)
		dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);

	return (n) ? IRQ_HANDLED : IRQ_NONE;
}
EXPORT_SYMBOL_GPL(sja1000_interrupt);

static int sja1000_open(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	int err;

	/* set chip into reset mode */
	set_reset_mode(dev);

	/* common open */
	err = open_candev(dev);
	if (err)
		return err;

	/* register interrupt handler, if not done by the device driver */
	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
		err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
				  dev->name, (void *)dev);
		if (err) {
			close_candev(dev);
			return -EAGAIN;
		}
	}

	/* init and start chi */
	sja1000_start(dev);
	priv->open_time = jiffies;

	netif_start_queue(dev);

	return 0;
}

static int sja1000_close(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	netif_stop_queue(dev);
	set_reset_mode(dev);

	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
		free_irq(dev->irq, (void *)dev);

	close_candev(dev);

	priv->open_time = 0;

	return 0;
}

struct net_device *alloc_sja1000dev(int sizeof_priv)
{
	struct net_device *dev;
	struct sja1000_priv *priv;

	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
		SJA1000_ECHO_SKB_MAX);
	if (!dev)
		return NULL;

	priv = netdev_priv(dev);

	priv->dev = dev;
	priv->can.bittiming_const = &sja1000_bittiming_const;
	priv->can.do_set_bittiming = sja1000_set_bittiming;
	priv->can.do_set_mode = sja1000_set_mode;

	if (sizeof_priv)
		priv->priv = (void *)priv + sizeof(struct sja1000_priv);

	return dev;
}
EXPORT_SYMBOL_GPL(alloc_sja1000dev);

void free_sja1000dev(struct net_device *dev)
{
	free_candev(dev);
}
EXPORT_SYMBOL_GPL(free_sja1000dev);

static const struct net_device_ops sja1000_netdev_ops = {
       .ndo_open               = sja1000_open,
       .ndo_stop               = sja1000_close,
       .ndo_start_xmit         = sja1000_start_xmit,
};

int register_sja1000dev(struct net_device *dev)
{
	if (!sja1000_probe_chip(dev))
		return -ENODEV;

	dev->flags |= IFF_ECHO;	/* we support local echo */
	dev->netdev_ops = &sja1000_netdev_ops;

	set_reset_mode(dev);
	chipset_init(dev);

	return register_candev(dev);
}
EXPORT_SYMBOL_GPL(register_sja1000dev);

void unregister_sja1000dev(struct net_device *dev)
{
	set_reset_mode(dev);
	unregister_candev(dev);
}
EXPORT_SYMBOL_GPL(unregister_sja1000dev);

static __init int sja1000_init(void)
{
	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);

	return 0;
}

module_init(sja1000_init);

static __exit void sja1000_exit(void)
{
	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
}

module_exit(sja1000_exit);
Commit	Line	Data
429da1cc WG	1	/*
	2	* sja1000.c - Philips SJA1000 network device driver
	3	*
	4	* Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
	5	* 38106 Braunschweig, GERMANY
	6	*
	7	* Copyright (c) 2002-2007 Volkswagen Group Electronic Research
	8	* All rights reserved.
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. Neither the name of Volkswagen nor the names of its contributors
	19	* may be used to endorse or promote products derived from this software
	20	* without specific prior written permission.
	21	*
	22	* Alternatively, provided that this notice is retained in full, this
	23	* software may be distributed under the terms of the GNU General
	24	* Public License ("GPL") version 2, in which case the provisions of the
	25	* GPL apply INSTEAD OF those given above.
	26	*
	27	* The provided data structures and external interfaces from this code
	28	* are not restricted to be used by modules with a GPL compatible license.
	29	*
	30	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	31	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	32	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	33	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	34	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	35	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	36	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	37	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	38	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	39	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	40	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
	41	* DAMAGE.
	42	*
	43	* Send feedback to <socketcan-users@lists.berlios.de>
	44	*
	45	*/
	46
	47	#include <linux/module.h>
	48	#include <linux/init.h>
	49	#include <linux/kernel.h>
	50	#include <linux/sched.h>
	51	#include <linux/types.h>
	52	#include <linux/fcntl.h>
	53	#include <linux/interrupt.h>
	54	#include <linux/ptrace.h>
	55	#include <linux/string.h>
	56	#include <linux/errno.h>
	57	#include <linux/netdevice.h>
	58	#include <linux/if_arp.h>
	59	#include <linux/if_ether.h>
	60	#include <linux/skbuff.h>
	61	#include <linux/delay.h>
	62
	63	#include <linux/can.h>
	64	#include <linux/can/dev.h>
65	#include <linux/can/error.h>
429da1cc WG	66
	67	#include "sja1000.h"
	68
	69	#define DRV_NAME "sja1000"
	70
	71	MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
	72	MODULE_LICENSE("Dual BSD/GPL");
	73	MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
	74
	75	static struct can_bittiming_const sja1000_bittiming_const = {
	76	.name = DRV_NAME,
	77	.tseg1_min = 1,
	78	.tseg1_max = 16,
	79	.tseg2_min = 1,
	80	.tseg2_max = 8,
	81	.sjw_max = 4,
	82	.brp_min = 1,
	83	.brp_max = 64,
	84	.brp_inc = 1,
	85	};
	86
	87	static int sja1000_probe_chip(struct net_device *dev)
	88	{
	89	struct sja1000_priv *priv = netdev_priv(dev);
	90
255a9154	91	if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
429da1cc WG	92	printk(KERN_INFO "%s: probing @0x%lX failed\n",
	93	DRV_NAME, dev->base_addr);
	94	return 0;
	95	}
	96	return -1;
	97	}
	98
	99	static void set_reset_mode(struct net_device *dev)
	100	{
	101	struct sja1000_priv *priv = netdev_priv(dev);
255a9154	102	unsigned char status = priv->read_reg(priv, REG_MOD);
429da1cc WG	103	int i;
	104
	105	/* disable interrupts */
255a9154	106	priv->write_reg(priv, REG_IER, IRQ_OFF);
429da1cc WG	107
	108	for (i = 0; i < 100; i++) {
	109	/* check reset bit */
	110	if (status & MOD_RM) {
	111	priv->can.state = CAN_STATE_STOPPED;
	112	return;
	113	}
	114
255a9154	115	priv->write_reg(priv, REG_MOD, MOD_RM); /* reset chip */
429da1cc	116	udelay(10);
255a9154	117	status = priv->read_reg(priv, REG_MOD);
429da1cc WG	118	}
	119
	120	dev_err(dev->dev.parent, "setting SJA1000 into reset mode failed!\n");
	121	}
	122
	123	static void set_normal_mode(struct net_device *dev)
	124	{
	125	struct sja1000_priv *priv = netdev_priv(dev);
255a9154	126	unsigned char status = priv->read_reg(priv, REG_MOD);
429da1cc WG	127	int i;
	128
	129	for (i = 0; i < 100; i++) {
	130	/* check reset bit */
	131	if ((status & MOD_RM) == 0) {
	132	priv->can.state = CAN_STATE_ERROR_ACTIVE;
	133	/* enable all interrupts */
255a9154	134	priv->write_reg(priv, REG_IER, IRQ_ALL);
429da1cc WG	135	return;
	136	}
	137
	138	/* set chip to normal mode */
255a9154	139	priv->write_reg(priv, REG_MOD, 0x00);
429da1cc	140	udelay(10);
255a9154	141	status = priv->read_reg(priv, REG_MOD);
429da1cc WG	142	}
	143
	144	dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n");
	145	}
	146
	147	static void sja1000_start(struct net_device *dev)
	148	{
	149	struct sja1000_priv *priv = netdev_priv(dev);
	150
	151	/* leave reset mode */
	152	if (priv->can.state != CAN_STATE_STOPPED)
	153	set_reset_mode(dev);
	154
	155	/* Clear error counters and error code capture */
255a9154 WG	156	priv->write_reg(priv, REG_TXERR, 0x0);
	157	priv->write_reg(priv, REG_RXERR, 0x0);
	158	priv->read_reg(priv, REG_ECC);
429da1cc WG	159
	160	/* leave reset mode */
	161	set_normal_mode(dev);
	162	}
	163
	164	static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
	165	{
	166	struct sja1000_priv *priv = netdev_priv(dev);
	167
	168	if (!priv->open_time)
	169	return -EINVAL;
	170
	171	switch (mode) {
	172	case CAN_MODE_START:
	173	sja1000_start(dev);
	174	if (netif_queue_stopped(dev))
	175	netif_wake_queue(dev);
	176	break;
	177
	178	default:
	179	return -EOPNOTSUPP;
	180	}
	181
	182	return 0;
	183	}
	184
	185	static int sja1000_set_bittiming(struct net_device *dev)
	186	{
	187	struct sja1000_priv *priv = netdev_priv(dev);
	188	struct can_bittiming *bt = &priv->can.bittiming;
	189	u8 btr0, btr1;
	190
	191	btr0 = ((bt->brp - 1) & 0x3f) \| (((bt->sjw - 1) & 0x3) << 6);
	192	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) \|
	193	(((bt->phase_seg2 - 1) & 0x7) << 4);
	194	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
	195	btr1 \|= 0x80;
	196
	197	dev_info(dev->dev.parent,
	198	"setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
	199
255a9154 WG	200	priv->write_reg(priv, REG_BTR0, btr0);
255a9154 WG	201	priv->write_reg(priv, REG_BTR1, btr1);
429da1cc WG	202
	203	return 0;
	204	}
	205
	206	/*
	207	* initialize SJA1000 chip:
	208	* - reset chip
	209	* - set output mode
	210	* - set baudrate
	211	* - enable interrupts
	212	* - start operating mode
	213	*/
	214	static void chipset_init(struct net_device *dev)
	215	{
	216	struct sja1000_priv *priv = netdev_priv(dev);
	217
	218	/* set clock divider and output control register */
255a9154	219	priv->write_reg(priv, REG_CDR, priv->cdr \| CDR_PELICAN);
429da1cc WG	220
429da1cc WG	221	/* set acceptance filter (accept all) */
255a9154 WG	222	priv->write_reg(priv, REG_ACCC0, 0x00);
	223	priv->write_reg(priv, REG_ACCC1, 0x00);
	224	priv->write_reg(priv, REG_ACCC2, 0x00);
	225	priv->write_reg(priv, REG_ACCC3, 0x00);
429da1cc	226
255a9154 WG	227	priv->write_reg(priv, REG_ACCM0, 0xFF);
	228	priv->write_reg(priv, REG_ACCM1, 0xFF);
	229	priv->write_reg(priv, REG_ACCM2, 0xFF);
	230	priv->write_reg(priv, REG_ACCM3, 0xFF);
429da1cc	231
255a9154	232	priv->write_reg(priv, REG_OCR, priv->ocr \| OCR_MODE_NORMAL);
429da1cc WG	233	}
	234
	235	/*
	236	* transmit a CAN message
	237	* message layout in the sk_buff should be like this:
	238	* xx xx xx xx ff ll 00 11 22 33 44 55 66 77
	239	* [ can-id ] [flags] [len] [can data (up to 8 bytes]
	240	*/
61357325 SH	241	static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
61357325 SH	242	struct net_device *dev)
429da1cc WG	243	{
429da1cc WG	244	struct sja1000_priv *priv = netdev_priv(dev);
429da1cc WG	245	struct can_frame cf = (struct can_frame )skb->data;
	246	uint8_t fi;
	247	uint8_t dlc;
	248	canid_t id;
	249	uint8_t dreg;
	250	int i;
	251
	252	netif_stop_queue(dev);
	253
	254	fi = dlc = cf->can_dlc;
	255	id = cf->can_id;
	256
	257	if (id & CAN_RTR_FLAG)
	258	fi \|= FI_RTR;
	259
	260	if (id & CAN_EFF_FLAG) {
	261	fi \|= FI_FF;
	262	dreg = EFF_BUF;
255a9154 WG	263	priv->write_reg(priv, REG_FI, fi);
	264	priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
	265	priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
	266	priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
	267	priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
429da1cc WG	268	} else {
429da1cc WG	269	dreg = SFF_BUF;
255a9154 WG	270	priv->write_reg(priv, REG_FI, fi);
	271	priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
	272	priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
429da1cc WG	273	}
	274
	275	for (i = 0; i < dlc; i++)
255a9154	276	priv->write_reg(priv, dreg++, cf->data[i]);
429da1cc	277
429da1cc WG	278	dev->trans_start = jiffies;
	279
	280	can_put_echo_skb(skb, dev, 0);
	281
255a9154	282	priv->write_reg(priv, REG_CMR, CMD_TR);
429da1cc	283
6ed10654	284	return NETDEV_TX_OK;
429da1cc WG	285	}
	286
	287	static void sja1000_rx(struct net_device *dev)
	288	{
	289	struct sja1000_priv *priv = netdev_priv(dev);
	290	struct net_device_stats *stats = &dev->stats;
	291	struct can_frame *cf;
	292	struct sk_buff *skb;
	293	uint8_t fi;
	294	uint8_t dreg;
	295	canid_t id;
429da1cc WG	296	int i;
429da1cc WG	297
c7cd606f	298	/* create zero'ed CAN frame buffer */
7b6856a0	299	skb = alloc_can_skb(dev, &cf);
429da1cc WG	300	if (skb == NULL)
429da1cc WG	301	return;
429da1cc	302
255a9154	303	fi = priv->read_reg(priv, REG_FI);
429da1cc WG	304
	305	if (fi & FI_FF) {
	306	/* extended frame format (EFF) */
	307	dreg = EFF_BUF;
255a9154 WG	308	id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
	309	\| (priv->read_reg(priv, REG_ID2) << (5 + 8))
	310	\| (priv->read_reg(priv, REG_ID3) << 5)
	311	\| (priv->read_reg(priv, REG_ID4) >> 3);
429da1cc WG	312	id \|= CAN_EFF_FLAG;
	313	} else {
	314	/* standard frame format (SFF) */
	315	dreg = SFF_BUF;
255a9154 WG	316	id = (priv->read_reg(priv, REG_ID1) << 3)
255a9154 WG	317	\| (priv->read_reg(priv, REG_ID2) >> 5);
429da1cc WG	318	}
429da1cc WG	319
c7cd606f	320	if (fi & FI_RTR) {
429da1cc	321	id \|= CAN_RTR_FLAG;
c7cd606f OH	322	} else {
	323	cf->can_dlc = get_can_dlc(fi & 0x0F);
	324	for (i = 0; i < cf->can_dlc; i++)
	325	cf->data[i] = priv->read_reg(priv, dreg++);
	326	}
429da1cc	327
429da1cc	328	cf->can_id = id;
429da1cc WG	329
429da1cc WG	330	/* release receive buffer */
255a9154	331	priv->write_reg(priv, REG_CMR, CMD_RRB);
429da1cc WG	332
	333	netif_rx(skb);
	334
429da1cc	335	stats->rx_packets++;
c7cd606f	336	stats->rx_bytes += cf->can_dlc;
429da1cc WG	337	}
	338
	339	static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
	340	{
	341	struct sja1000_priv *priv = netdev_priv(dev);
	342	struct net_device_stats *stats = &dev->stats;
	343	struct can_frame *cf;
	344	struct sk_buff *skb;
	345	enum can_state state = priv->can.state;
	346	uint8_t ecc, alc;
	347
7b6856a0	348	skb = alloc_can_err_skb(dev, &cf);
429da1cc WG	349	if (skb == NULL)
429da1cc WG	350	return -ENOMEM;
429da1cc WG	351
	352	if (isrc & IRQ_DOI) {
	353	/* data overrun interrupt */
	354	dev_dbg(dev->dev.parent, "data overrun interrupt\n");
	355	cf->can_id \|= CAN_ERR_CRTL;
	356	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
	357	stats->rx_over_errors++;
	358	stats->rx_errors++;
255a9154	359	priv->write_reg(priv, REG_CMR, CMD_CDO); /* clear bit */
429da1cc WG	360	}
	361
	362	if (isrc & IRQ_EI) {
	363	/* error warning interrupt */
	364	dev_dbg(dev->dev.parent, "error warning interrupt\n");
	365
	366	if (status & SR_BS) {
	367	state = CAN_STATE_BUS_OFF;
	368	cf->can_id \|= CAN_ERR_BUSOFF;
	369	can_bus_off(dev);
	370	} else if (status & SR_ES) {
	371	state = CAN_STATE_ERROR_WARNING;
	372	} else
	373	state = CAN_STATE_ERROR_ACTIVE;
	374	}
	375	if (isrc & IRQ_BEI) {
	376	/* bus error interrupt */
	377	priv->can.can_stats.bus_error++;
	378	stats->rx_errors++;
	379
255a9154	380	ecc = priv->read_reg(priv, REG_ECC);
429da1cc WG	381
	382	cf->can_id \|= CAN_ERR_PROT \| CAN_ERR_BUSERROR;
	383
	384	switch (ecc & ECC_MASK) {
	385	case ECC_BIT:
	386	cf->data[2] \|= CAN_ERR_PROT_BIT;
	387	break;
	388	case ECC_FORM:
	389	cf->data[2] \|= CAN_ERR_PROT_FORM;
	390	break;
	391	case ECC_STUFF:
	392	cf->data[2] \|= CAN_ERR_PROT_STUFF;
	393	break;
	394	default:
	395	cf->data[2] \|= CAN_ERR_PROT_UNSPEC;
	396	cf->data[3] = ecc & ECC_SEG;
	397	break;
	398	}
	399	/* Error occured during transmission? */
	400	if ((ecc & ECC_DIR) == 0)
	401	cf->data[2] \|= CAN_ERR_PROT_TX;
	402	}
	403	if (isrc & IRQ_EPI) {
	404	/* error passive interrupt */
	405	dev_dbg(dev->dev.parent, "error passive interrupt\n");
	406	if (status & SR_ES)
	407	state = CAN_STATE_ERROR_PASSIVE;
	408	else
	409	state = CAN_STATE_ERROR_ACTIVE;
	410	}
	411	if (isrc & IRQ_ALI) {
	412	/* arbitration lost interrupt */
	413	dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
255a9154	414	alc = priv->read_reg(priv, REG_ALC);
429da1cc	415	priv->can.can_stats.arbitration_lost++;
8935f57e	416	stats->tx_errors++;
429da1cc WG	417	cf->can_id \|= CAN_ERR_LOSTARB;
	418	cf->data[0] = alc & 0x1f;
	419	}
	420
	421	if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING \|\|
	422	state == CAN_STATE_ERROR_PASSIVE)) {
255a9154 WG	423	uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
255a9154 WG	424	uint8_t txerr = priv->read_reg(priv, REG_TXERR);
429da1cc WG	425	cf->can_id \|= CAN_ERR_CRTL;
	426	if (state == CAN_STATE_ERROR_WARNING) {
	427	priv->can.can_stats.error_warning++;
	428	cf->data[1] = (txerr > rxerr) ?
	429	CAN_ERR_CRTL_TX_WARNING :
	430	CAN_ERR_CRTL_RX_WARNING;
	431	} else {
	432	priv->can.can_stats.error_passive++;
	433	cf->data[1] = (txerr > rxerr) ?
	434	CAN_ERR_CRTL_TX_PASSIVE :
	435	CAN_ERR_CRTL_RX_PASSIVE;
	436	}
	437	}
	438
	439	priv->can.state = state;
	440
	441	netif_rx(skb);
	442
429da1cc WG	443	stats->rx_packets++;
	444	stats->rx_bytes += cf->can_dlc;
	445
	446	return 0;
	447	}
	448
	449	irqreturn_t sja1000_interrupt(int irq, void *dev_id)
	450	{
	451	struct net_device dev = (struct net_device )dev_id;
	452	struct sja1000_priv *priv = netdev_priv(dev);
	453	struct net_device_stats *stats = &dev->stats;
	454	uint8_t isrc, status;
	455	int n = 0;
	456
	457	/* Shared interrupts and IRQ off? */
255a9154	458	if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
429da1cc WG	459	return IRQ_NONE;
	460
	461	if (priv->pre_irq)
255a9154	462	priv->pre_irq(priv);
429da1cc	463
255a9154	464	while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
429da1cc	465	n++;
255a9154	466	status = priv->read_reg(priv, REG_SR);
429da1cc WG	467
	468	if (isrc & IRQ_WUI)
	469	dev_warn(dev->dev.parent, "wakeup interrupt\n");
	470
	471	if (isrc & IRQ_TI) {
	472	/* transmission complete interrupt */
8935f57e	473	stats->tx_bytes += priv->read_reg(priv, REG_FI) & 0xf;
429da1cc WG	474	stats->tx_packets++;
	475	can_get_echo_skb(dev, 0);
	476	netif_wake_queue(dev);
	477	}
	478	if (isrc & IRQ_RI) {
	479	/* receive interrupt */
	480	while (status & SR_RBS) {
	481	sja1000_rx(dev);
255a9154	482	status = priv->read_reg(priv, REG_SR);
429da1cc WG	483	}
	484	}
	485	if (isrc & (IRQ_DOI \| IRQ_EI \| IRQ_BEI \| IRQ_EPI \| IRQ_ALI)) {
	486	/* error interrupt */
	487	if (sja1000_err(dev, isrc, status))
	488	break;
	489	}
	490	}
	491
	492	if (priv->post_irq)
255a9154	493	priv->post_irq(priv);
429da1cc WG	494
	495	if (n >= SJA1000_MAX_IRQ)
	496	dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
	497
	498	return (n) ? IRQ_HANDLED : IRQ_NONE;
	499	}
	500	EXPORT_SYMBOL_GPL(sja1000_interrupt);
	501
	502	static int sja1000_open(struct net_device *dev)
	503	{
	504	struct sja1000_priv *priv = netdev_priv(dev);
	505	int err;
	506
	507	/* set chip into reset mode */
	508	set_reset_mode(dev);
	509
	510	/* common open */
	511	err = open_candev(dev);
	512	if (err)
	513	return err;
	514
	515	/* register interrupt handler, if not done by the device driver */
	516	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
4c9ba61e	517	err = request_irq(dev->irq, sja1000_interrupt, priv->irq_flags,
429da1cc WG	518	dev->name, (void *)dev);
429da1cc WG	519	if (err) {
429da1cc	520	close_candev(dev);
128ced8f	521	return -EAGAIN;
429da1cc WG	522	}
	523	}
	524
	525	/* init and start chi */
	526	sja1000_start(dev);
	527	priv->open_time = jiffies;
	528
	529	netif_start_queue(dev);
	530
	531	return 0;
	532	}
	533
	534	static int sja1000_close(struct net_device *dev)
	535	{
	536	struct sja1000_priv *priv = netdev_priv(dev);
	537
	538	netif_stop_queue(dev);
	539	set_reset_mode(dev);
	540
	541	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
	542	free_irq(dev->irq, (void *)dev);
	543
	544	close_candev(dev);
	545
	546	priv->open_time = 0;
	547
	548	return 0;
	549	}
	550
	551	struct net_device *alloc_sja1000dev(int sizeof_priv)
	552	{
	553	struct net_device *dev;
	554	struct sja1000_priv *priv;
	555
a6e4bc53 WG	556	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv,
a6e4bc53 WG	557	SJA1000_ECHO_SKB_MAX);
429da1cc WG	558	if (!dev)
	559	return NULL;
	560
	561	priv = netdev_priv(dev);
	562
	563	priv->dev = dev;
	564	priv->can.bittiming_const = &sja1000_bittiming_const;
	565	priv->can.do_set_bittiming = sja1000_set_bittiming;
	566	priv->can.do_set_mode = sja1000_set_mode;
	567
	568	if (sizeof_priv)
	569	priv->priv = (void *)priv + sizeof(struct sja1000_priv);
	570
	571	return dev;
	572	}
	573	EXPORT_SYMBOL_GPL(alloc_sja1000dev);
	574
	575	void free_sja1000dev(struct net_device *dev)
	576	{
	577	free_candev(dev);
	578	}
	579	EXPORT_SYMBOL_GPL(free_sja1000dev);
	580
	581	static const struct net_device_ops sja1000_netdev_ops = {
	582	.ndo_open = sja1000_open,
	583	.ndo_stop = sja1000_close,
	584	.ndo_start_xmit = sja1000_start_xmit,
	585	};
	586
	587	int register_sja1000dev(struct net_device *dev)
	588	{
	589	if (!sja1000_probe_chip(dev))
	590	return -ENODEV;
	591
	592	dev->flags \|= IFF_ECHO; /* we support local echo */
	593	dev->netdev_ops = &sja1000_netdev_ops;
	594
	595	set_reset_mode(dev);
	596	chipset_init(dev);
	597
	598	return register_candev(dev);
	599	}
	600	EXPORT_SYMBOL_GPL(register_sja1000dev);
	601
	602	void unregister_sja1000dev(struct net_device *dev)
	603	{
	604	set_reset_mode(dev);
	605	unregister_candev(dev);
	606	}
	607	EXPORT_SYMBOL_GPL(unregister_sja1000dev);
	608
	609	static __init int sja1000_init(void)
	610	{
	611	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
	612
	613	return 0;
	614	}
	615
	616	module_init(sja1000_init);
	617
	618	static __exit void sja1000_exit(void)
	619	{
	620	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
	621	}
622
623	module_exit(sja1000_exit);